The S3 direct upload managed mode introduced by
NXP-29319 uses a customer-supplied key as the blob key in storage. Instead, we should use the S3 ETag directly, which has two advantages:
- It avoids relying on client information.
- It still provides a limited form of deduplication, if by chance another client uploads the same blob using the same multipart chunking parameters then the ETags will be the same and deduplication will occur.